1. Technical Field
The present invention relates to a method for designing a spectacle lens mounted in a spectacle frame having a large bend angle, such as a wraparound-type spectacle frame, a spectacle lens, and a pair of spectacles mounted in a spectacle frame.
2. Description of the Related Art
Currently, a wraparound-type spectacle frame, which is mainly used for sports glasses, has been increasingly used in activities other than sports. FIGS. 3A and 3B are perspective views of an example of a wraparound-type spectacle frame as viewed obliquely and from above, respectively. The wraparound-type spectacle frame illustrated in FIGS. 3A and 3B has a large bend angle, which is contoured with the shape of the wearer's face. As a result, lenses mounted in the wraparound-type spectacle frame extend to the sides of the face, and provide a wide panning range for viewing. Because of this feature, the wraparound-type spectacle frame is ideal for use in sports, for example, to provide eye protection specifically during athletic activity.
With the rise in the number of the athletes wearing wraparound-type spectacle frames, the number of non-athletes wearing the wraparound-type spectacle frames is also increasing. As a result, the number of people who require corrective lenses and desire to wear the wraparound-type spectacle frame is also increasing.
In order to meet this demand, JP-A-2005-284059 discloses an optical design method for a wraparound-type spectacle frame having a large bend angle.
However, the above reference discloses only correction for the effects of the bend angle and the pantoscopic angle. Although individuals with astigmatism desire to use wraparound-type spectacle frames, this technique does not provide a method for creating a lens that corrects astigmatism in wraparound-type spectacle frames.